/*
 * ProGuard -- shrinking, optimization, obfuscation, and preverification of Java bytecode.
 *
 * Copyright (c) 2002-2018 GuardSquare NV
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with this program; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
package proguard;

import java.io.IOException;

import proguard.classfile.util.WarningPrinter;

/**
 * This class performs sanity checks on a given configurations.
 *
 * @author Eric Lafortune
 */
public class ConfigurationChecker {
    private final Configuration configuration;

    /**
     * Creates a new ConfigurationChecker with the given configuration.
     */
    public ConfigurationChecker(Configuration configuration) {
        this.configuration = configuration;
    }

    /**
     * Checks the given configuration for potential problems.
     */
    public void check() throws IOException {
        ClassPath programJars = configuration.programJars;
        ClassPath libraryJars = configuration.libraryJars;

        // Check that the input isn't empty.
        if (programJars == null) {
            throw new IOException("The input is empty. You have to specify one or more '-injars' options.");
        }

        // Check that the first jar is an input jar.
        ClassPathEntry firstEntry = programJars.get(0);
        if (firstEntry.isOutput()) {
            throw new IOException("The output jar [" + firstEntry.getName()
                + "] must be specified after an input jar, or it will be empty.");
        }

        // Check that the first of two subsequent the output jars has a filter.
        for (int index = 0; index < programJars.size() - 1; index++) {
            ClassPathEntry entry = programJars.get(index);
            if (entry.isOutput() && !entry.isFiltered() && programJars.get(index + 1).isOutput()) {
                throw new IOException("The output jar [" + entry.getName()
                    + "] must have a filter, or all subsequent output jars will be empty.");
            }
        }

        // Check for conflicts between input/output entries of the class paths.
        checkConflicts(programJars, programJars);
        checkConflicts(programJars, libraryJars);
        checkConflicts(libraryJars, libraryJars);

        // Print out some general notes if necessary.
        if ((configuration.note == null || !configuration.note.isEmpty())) {
            // Check for potential problems with mixed-case class names on
            // case-insensitive file systems.
            if (configuration.obfuscate && configuration.useMixedCaseClassNames
                && configuration.classObfuscationDictionary == null) {
                String os = System.getProperty("os.name").toLowerCase();
                if (os.startsWith("windows") || os.startsWith("mac os")) {
                    // Go over all program class path entries.
                    for (int index = 0; index < programJars.size(); index++) {
                        // Is it an output directory?
                        ClassPathEntry entry = programJars.get(index);
                        if (entry.isOutput() && !entry.isApk() && !entry.isJar() && !entry.isAar() && !entry.isWar()
                            && !entry.isEar() && !entry.isJmod() && !entry.isZip()) {
                            System.out.println("Note: you're writing the processed class files to a directory ["
                                + entry.getName() + "].");
                            System.out.println(
                                "      This will likely cause problems with obfuscated mixed-case class names.");
                            System.out
                                .println("      You should consider writing the output to a jar file, or otherwise");
                            System.out.println("      specify '-dontusemixedcaseclassnames'.");

                            break;
                        }
                    }
                }
            }

            // Check if -adaptresourcefilecontents has a proper filter.
            if (configuration.adaptResourceFileContents != null && (configuration.adaptResourceFileContents.isEmpty()
                || configuration.adaptResourceFileContents.get(0).equals(ConfigurationConstants.ANY_FILE_KEYWORD))) {
                System.out.println("Note: you're specifying '-adaptresourcefilecontents' for all resource files.");
                System.out.println("      This will most likely cause problems with binary files.");
            }

            // Check if all -keepclassmembers options indeed have class members.
            WarningPrinter keepClassMemberNotePrinter = new WarningPrinter(System.out, configuration.note);

            new KeepClassMemberChecker(keepClassMemberNotePrinter).checkClassSpecifications(configuration.keep);

            // Check if -assumenosideffects options don't specify all methods.
            WarningPrinter assumeNoSideEffectsNotePrinter = new WarningPrinter(System.out, configuration.note);

            new AssumeNoSideEffectsChecker(assumeNoSideEffectsNotePrinter)
                .checkClassSpecifications(configuration.assumeNoSideEffects);

            // Print out a summary of the notes, if necessary.
            int keepClassMemberNoteCount = keepClassMemberNotePrinter.getWarningCount();
            if (keepClassMemberNoteCount > 0) {
                System.out.println("Note: there were " + keepClassMemberNoteCount
                    + " '-keepclassmembers' options that didn't specify class");
                System.out.println("      members. You should specify at least some class members or consider");
                System.out.println("      if you just need '-keep'.");
                System.out.println("      (http://proguard.sourceforge.net/manual/troubleshooting.html#classmembers)");
            }

            int assumeNoSideEffectsNoteCount = assumeNoSideEffectsNotePrinter.getWarningCount();
            if (assumeNoSideEffectsNoteCount > 0) {
                System.out.println("Note: there were " + assumeNoSideEffectsNoteCount
                    + " '-assumenosideeffects' options that try to match all");
                System.out.println("      methods with wildcards. This will likely cause problems with methods like");
                System.out.println("      'wait()' and 'notify()'. You should specify the methods more precisely.");
                System.out.println("      (http://proguard.sourceforge.net/manual/troubleshooting.html#nosideeffects)");
            }
        }
    }

    /**
     * Performs some sanity checks on the class paths.
     */
    private void checkConflicts(ClassPath classPath1, ClassPath classPath2) throws IOException {
        if (classPath1 == null || classPath2 == null) {
            return;
        }

        for (int index1 = 0; index1 < classPath1.size(); index1++) {
            ClassPathEntry entry1 = classPath1.get(index1);

            for (int index2 = 0; index2 < classPath2.size(); index2++) {
                if (classPath1 != classPath2 || index1 != index2) {
                    ClassPathEntry entry2 = classPath2.get(index2);

                    if (entry2.getName().equals(entry1.getName())) {
                        if (entry1.isOutput()) {
                            if (entry2.isOutput()) {
                                // Output / output.
                                throw new IOException(
                                    "The same output jar [" + entry1.getName() + "] is specified twice.");
                            } else {
                                // Output / input.
                                throw new IOException(
                                    "Input jars and output jars must be different [" + entry1.getName() + "].");
                            }
                        } else {
                            if (entry2.isOutput()) {
                                // Input / output.
                                throw new IOException(
                                    "Input jars and output jars must be different [" + entry1.getName() + "].");
                            } else if (!entry1.isFiltered() || !entry2.isFiltered()) {
                                // Input / input.
                                throw new IOException(
                                    "The same input jar [" + entry1.getName() + "] is specified twice.");
                            }
                        }
                    }
                }
            }
        }
    }
}
